ADVERTISEMENT
Anomalous Right Coronary Artery Origin from the Pulmonary Artery (ARCAPA) Coexisting with Obstructive Atherosclerotic Disease of the Left Coronary Artery
Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital coronary anomaly; it is even more exceptional in adults.1 ARCAPA has been diagnosed as an isolated abnormality and has also been described in conjunction with other congenital abnormalities, including bicuspid aortic valve disease, atrial septal defects and tetralogy of Fallot.1,2 The clinical presentation of individuals with ARCAPA varies from those who are asymptomatic to individuals with symptoms and signs of myocardial ischemia, heart failure and even sudden death. The majority of ARCAPA cases are diagnosed in childhood, with few cases reported in adults.1 We present an individual with ARCAPA diagnosed by coronary angiography at age 77, who presented with atrial fibrillation and co-existing obstructive disease of the left coronary system.
Case Report. A 77-year-old female underwent coronary angiography to evaluate an abnormal dipyridamole myocardial perfusion study. She had presented to the emergency room after an episode of syncope and was found to be in atrial fibrillation with rapid ventricular response. She spontaneously converted to normal sinus rhythm and was admitted to the hospital.
Her past medical history included hypertension, life-long tobacco use, non-exertional chest discomfort and dyspnea on exertion. A year prior, she had been diagnosed with symptomatic peripheral arterial disease and had undergone percutaneous angioplasty and stent placement to both external iliac arteries.
On physical examination, she appeared chronically ill and her respiratory status was mildly labored at rest. Blood pressure was 142/64 mmHg; heart rate was 60 bpm and regular. The jugular venous pressure was 10 cms H2O. Bibasilar rales and faint end-expiratory wheezing were audible. A soft systolic murmur was heard at the lower sternal border. Bilateral femoral bruits were present and the pedal pulses were palpable but of reduced magnitude. There was no peripheral edema.
Admission blood studies were normal except for hemoglobin 9.1 gm/dl. Cardiac biomarkers were normal. Her electrocardiogram revealed normal sinus rhythm with non-specific T-wave abnormalities.
Transthoracic-echocardiograpy demonstrated normal left ventricular systolic wall motion and concentric left ventricular hypertrophy (estimated ejection fraction, 65%; left ventricular wall thickness, 14 mm), mild mitral and moderate tricuspid regurgitation (TR velocity, 3.3 m/s). Dipyridamole technitium-99m Myoview imaging (GE Healthcare, Wawatausa, Wisconsin) demonstrated areas of fixed perfusion defects in the posterobasal and inferior walls, with mild reversible perfusion defects in the high anterolateral and low posterolateral walls. Given these findings, the patient was referred for coronary angiography.
Left coronary artery angiography via right femoral artery access showed mild atherosclerosis of the left main and left anterior descending coronary arteries. Severe 
subtotal occlusion of the proximal circumflex coronary was demonstrated, with a long diseased segment extending into a circumflex marginal branch. A dilated right coronary artery (RCA) filled via left-to-right collateral vessels and emptied into the pulmonary artery (Figures 1 and 2). The RCA was not identified with injection of contrast into the Sinus of Valsalva.
Right heart catheterization with oximetric analysis revealed elevated filling pressures, 
moderate pulmonary hypertension, a preserved cardiac index at rest with no detectable left-to-right shunt by oximetry (mean right atrial pressure, 13 mmHg; pulmonary artery pressure, 65/25 mmHg; mean, 43 mmHg; and mean pulmonary capillary wedge pressure, 30 mmHg; superior vena cava saturation, 54.6%; inferior vena cava, 54.8%; pulmonary artery, 49.8%; calculated pulmonary (QP) and systemic (QS) blood flow, 3.8 liters/minute with QP/QS 1.0; calculated pulmonary and systemic vascular resistance, 2.4 and 25.8 wood units, respectively; calculated Fick cardiac index, 2.2 liters/minute/m2).
Considering the catheterization data, the patient’s underlying lung disease, her advanced age and general deconditioning, medical therapy was instituted, aimed at pre-load reduction, blood pressure and rhythm control and secondary atherosclerotic prevention, reserving surgical revascularization of the RCA and circumflex marginal for medically refractory ischemic symptoms.
Discussion. Anomalous origin of a coronary artery from the pulmonary artery is a rare anomaly, with an estimated incidence of about 1 in 100,000 births,3 the vast majority of which involve anomalous origin of the left coronary from the pulmonary artery (ALCAPA, also known as Bland-Garland-White syndrome).4 ARCAPA is so rare that the true incidence is unknown. Published reports suggest that it accounts for 0.12% of all coronary artery anomalies, with an estimated incidence of ARCAPA in the general population of 0.002%.5
The original report of ARCAPA, and many of the early published reports, was diagnosed at autopsy. About 50 individuals with ARCAPA have been reported in the literature.6 The vast majority were diagnosed in infancy and childhood, with the diagnosis most frequently made using transthoracic echocardiography. The diagnosis of ARCAPA during adult life is exceedingly rare.1 The patient presented in this report represents the oldest patient diagnosed with congenital anomalous origin of the RCA from the pulmonary artery.
Like ALCAPA, ARCAPA coronary physiology is one of reversed coronary flow in the anomalous coronary connected to the low-pressure pulmonary bed, resulting in “coronary steal” physiology into the pulmonary artery.7 While perhaps less malignant than ALCAPA, survival with ARCAPA likewise depends on the development of a rich system of collaterals from the contralateral coronary bed.
Children diagnosed with this anomaly are typically treated with surgical revascularization given the known morbidity of this abnormal coronary circulation, the reports of sudden death, and the paucity of patients with this uncorrected anomaly that reach adulthood. The patient presented had elevated right- and left-sided filling pressures with normal left ventricular systolic function. This diastolic dysfunction was likely related to a combination of hypertensive and ischemic heart disease, and contributed to the development of atrial fibrillation and her clinical presentation. The vasodilator perfusion imaging defects seen on the radionuclide study likely reflect a combination of her atherosclerotic obstructive coronary disease in the circumflex system as well as the coronary “steal” physiology caused by the anomalous RCA.
The patient presented in this paper represents the exceptional clinical course of a rare congenital coronary anomaly, presenting with preserved systolic myocardial function at age 77, the clinical presentation governed by symptoms of coexistent atrial arrhythmias and atherosclerotic vascular disease.
Editor’s Note
This case illustrates an extremely rare coronary anomaly encountered in adults and clear depiction of angiographic views when anomalous origin of coronary arteries from the pulmonary artery is suspected. Also, these cases are medically managed once detected in old age.
— Samin K. Sharma, MD, Mount Sinai Medical Center, New York, New York
References
1. Williams IA, Gersony WM, Hellenbrand WE. Anomalous right coronary artery arising from the pulmonary artery: A report of 7 cases and a review of the literature. Am Heart J 2006;152:1004-E9–1004-E17. 2. Bossert T, Walther T, Doll N, et al. Anomalous origin of the right coronary artery from the pulmonary artery combined with aortic valve stenosis. Ann Thorac Surg 2005;79:347–348. 3. Vouhe PR, Baillot-Vernant F, Trinquet F, et al. Anomalous left coronary artery from the pulmonary artery in infants. Which operation? When? J Thorac Cardiovasc Surg 1987;94:192–199. 4. Kreutzer C, Schlichter AJ, Roman MI, Kreutzer GO. Emergency ligation of anomalous left coronary artery arising from the pulmonary artery. Ann Thorac Surg 2000;69:1591–1592. 5. Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn 1990;21:28–40. 6. Kajihara N, Asou T, Takeda Y, Kosaka Y. Surgical treatment of an infant with myocardial ischemia due to an anomalous origin of the right coronary artery from the main pulmonary artery: Report of a case. Surg Today 2009;39:969–971. 7. Sabiston DC Jr., Neill CA, Taussig HB. The direction of blood flow in anomalous left coronary artery arising from the pulmonary artery. Circulation 1960;22:591–597.
